Constitutional DNA copy number changes in ICSI children.
BACKGROUND
Over the last three decades, technological developments facilitating assisted reproductive techniques (ART) have revolutionized the treatment of subfertile couples, including men suffering from severe oligospermia or azoospermia. In parallel with the advent of these technologies, there is a great concern about the biological safety of ART. This concern is supported by the clinical observation that the frequency of congenital malformations is slightly elevated among ART-conceived children.


METHODS
In this explorative study, we have used tiling-resolution BAC array-mediated comparative genomic hybridization to investigate the incidence of de novo genomic copy number changes in a group of 12 ICSI children, compared with a control group of 30 naturally conceived children.


RESULTS
In 6 of the 12 ICSI children, we found 10 apparently de novo 'same direction genomic copy number changes' [i.e. simultaneous copy number gain (or loss) with respect to both biological parents], notably losses. In statistically significant contrast, similar observations were encountered only six times in the control group in 5 of the 30 children. However, our study group was small, so a larger group is needed to confirm these findings.


CONCLUSIONS
Loci at which we found de novo alterations are known from the human genome database to be prone to large DNA segment copy number changes. As discussed, various molecular mechanisms, including the consequences of delayed male meiotic synapsis and replication fork stalling at early embryonic cell cycles, might trigger these copy number changes.
Woldringh
G H
GH
Department of Obstetrics and Gynecology (internal postal code 791), Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands.
Janssen
I M
IM
Hehir-Kwa
J Y
JY
van den Elzen
C
C
Kremer
J A M
JA
de Boer
P
P
Schoenmakers
E F P M
EF
D016022:Case-Control Studies; D055028:Comparative Genomic Hybridization; D004247:DNA / Q000737:chemistry*; D018628:Gene Dosage; D015894:Genome, Human; D006239:Haplotypes; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D018570:Risk Assessment; D017422:Sequence Analysis, DNA; D020554:Sperm Injections, Intracytoplasmic
D004247:DNA